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(No Model.)

J. BURKHARDT.

METHOD OF FORMING ORNAMENTAL TUBING OR TUBULAR CUPS.

No. 425,022. Patented Apr. 8, 1890.

Jm/EIWUF Wimsssss UNITED STATES PATENT OFFICE.

JOHN BURKHARDT, OF NEWV YORK, N. Y.

METHOD OF FORMING ORNAMENTAL TUBING 0R TlJBULAR CUPS.

SPECIFICATION forming part of Letters Patent No. 425,022, dated Apri1'8, 1890.

Application filed July 22, 1889. Serial No. 318,203. (No model.)

To all whom it may concern;

Be it known that I, JOHN BURKHARDT, a citizen of the United States, residing at New York, in the county and State of New York, have invented a new and useful Improvement in the Method of Forming Ornamental Tubing or Tubular Cups, of which the following is a full, clear, and, exact description, reference being had to the accompanying drawings, forming part of this specification.

In the drawings, Figure 1 represents a plain piece of metal tubing. Fig. 2 represents said tubing with its diameter reduced at regular distances apart. Fig. 3 shows a vertical section of the tubing partly finished by my improved process and exhibits one-half of two pairs of dies employed for the purpose and the open table of a press. Fig. 4 represents aportion of tubing finished. Fig.5 represents a perspective view of one-half of two sets of the dies detached. Fig. 6 represents a plan or top View of a pair of the dies embraced by removable clamps or yokes; and Fig. 7 is a modified view of the parts represented in Fig. 3 in vertical section, exhibiting the dies as closed and pressed together.

The object of my present invention is to form plain metal tubing or rolls of sheet metal into articles of ornamental configuration by first reducing the circumference of the tubing at certain distances or intervals throughout its length and then increasing or enlarging its circumference at intervals or places between the reduced or lessened circumference by means of dies and a press for actuating them, as hereinafter set forth.

In my patent dated March 26, 1889, and numbered 400,394., I have described certain means for impressing upon metal tubing ornamental forms, by which means the form represented in Fig. 2 of the drawings may be produced; but the reduced diameter at any desired distances apart, or as shown in said figure, may be obtained by the use of rolls of the proper configuration, between which the plain piece of tubing may be placed for reduction.

The piece of tubing similar to that shown in Fig. 2 of the drawings, whether the distances between the lines denoting reduction of the circumference be the same or vary in extent, (the tube so reduced,) will be placed between two sets of dies A and B, which will embrace the girdled tube, Fig. 2, and the open space between said two sets of dies will depend on the dimensions of the globe or section of said tube that will be between them on each occasion of their use, as represented in Fig. 13 at X. Said dies will be closed together around the tube and secured by hinged yokes or clamps C C, as shown in Fig. 6.

To assure accuracy of position of the dies upon the tube and to guide them in their approach to each other, dowel-pins P P, attached to one of the dies of each pair, will enter correspondingholes formed in the counterparts of the dies, and similar dowel-pins S S are employed to enter holes in their counterparts to govern the action of the two pairs of dies as they are forced together. The upper and the lower concavities i 2' of the respective dies are made of proper shape and capacity to correspond with the size and figure of the globular or oval sections of the tubing, so that their use will not change the shape or size of said sections above and below the working widened concavities J J of the respective pairs of dies.

The counterparts of the dies A B are not shown, except in Fig. 6, where the upper set of dies A is represented within its yoke G. The form of the concavities J of one pair of the dies may be made to differ in shape or size from that of the other pair, so that the upper and lower halves of the section of tubing subjected to their action to enlarge the circumference by their use will represent correspondingly different shapes or sizes-that is to say, by varying the form of concavities J of the lower set of dies B from the form of the concavities 1 of the upper set of dies A that section or globular portion of a tube upon which such dies will act will necessarily be reduced to the configuration representing said different concavities of the dies. For instance, the lower set of dies may have concavities of the exact shape of one-half of an acorn and the upper pair of dies may be of the conical shape of the upper half of the acorn, and by similar variations of the dies ornamental designs in great variety may be impressed upon sections of tubing to be used to einbellish different classes of artistic metal wor z.

hen the two pairs of dies are placed aronndthe prepared piece of tubing, as shown in section, Figs. 3 and 6, the lower set of (lies will be seated upon the table D of a press having an opening through which the tubing will extend, and the upper pair of dies will be subjected to the downward action of the press, when both pairs of dies will approach each other and cause that portion of the tubing between them to be partially flattened and its circumference will be enlarged, as shown in Figs. 3 and 7.

Having described in y invention, I claim and desire to secure by Letters Patent The herein-described method or process of l'Vitnesses:

I'IERBERT W. HEYER, WM. K. WATERMAN. 

